Dermatology drugs include both topical and internal use, two categories. Topical drugs play very important role in the treatment and prevention of skin disease. It can be administrated in direct contact with the skin lesions to exert its function. The local drug concentration is high with remarkable efficacy. It can also avoid or reduce the adverse reaction emerged during the process of the in vivo metabolism of the oral administrated drug, therefore can be used in large amount. As the topical drugs need to be absorbed through the skin in order to exert a better systemic effect, the drug's percutaneous absorption also follows the general laws of drug absorption, however, the process of percutaneous absorption and the related impact factors of the topical drugs are also different from that of the oral administrated drugs.
The major formulations of the dermatology topical drugs include ointment, cream, gel and solution, etc., drugs are related to anti-infective drugs, keratolytic drugs, adrenal corticosteroids drugs and disinfection antiseptic drugs. It is generally required to be subject to local administration, not suitable for oral or long-term, high-dose administration.